Jesus also said this: Then said he unto them, But now, he that hath a purse, let him take it, and likewise his scrip: and he that hath no sword, let him sell his garment, and buy one. (Luke 22:36)
Why did He say this if swords were not meant for self-defense? What you quoted was taken out of context, since that is a reference to either soldiers or murderers. Peter was not supposed to be defending Christ with his sword.
Mat 26:51 And, behold, one of them which were with Jesus stretched out his hand, and drew his sword, and struck a servant of the high priest's, and smote off his ear.
Mat 26:52 Then said Jesus unto him, Put up again thy sword into his place: for all they that take the sword shall perish with the sword.
Rev 13:10 He that leadeth into captivity shall go into captivity: he that killeth with the sword must be killed with the sword. Here is the patience and the faith of the saints.
The world fights physically for their beliefs to preserve them and extend them.
The saints are not to fight physically for the kingdom of God..
Some people think that in the garden it was not alright to use the sword but they can use it in another situation.
But Jesus said all people that use the sword will perish with the sword.
That includes everyone so it does not matter the situation.
Luk 3:14 And the soldiers likewise demanded of him, saying, And what shall we do? And he said unto them, Do violence to no man, neither accuse any falsely; and be content with your wages.
Rom 12:19 Dearly beloved, avenge not yourselves, but rather give place unto wrath: for it is written, Vengeance is mine; I will repay, saith the Lord.
Rom 12:20 Therefore if thine enemy hunger, feed him; if he thirst, give him drink: for in so doing thou shalt heap coals of fire on his head.
Rom 12:21 Be not overcome of evil, but overcome evil with good.
John the Baptist told the soldiers to do no violence to a person.
And God said do not avenge yourselves for He will avenge.
Luk 22:35 And he said unto them, When I sent you without purse, and scrip, and shoes, lacked ye any thing? And they said, Nothing.
Luk 22:36 Then said he unto them, But now, he that hath a purse, let him take it, and likewise his scrip: and he that hath no sword, let him sell his garment, and buy one.
Luk 22:37 For I say unto you, that this that is written must yet be accomplished in me, And he was reckoned among the transgressors: for the things concerning me have an end.
Luk 22:38 And they said, Lord, behold, here are two swords. And he said unto them, It is enough.
They went out looking innocent and no harm intention at the first.
Jesus tells his disciples to buy a sword primarily to fulfill the prophesy that He would be numbered among the transgressors(Luke 22:37, Isaiah 53:12), not to lead an armed revolt or for personal protection.
To be crucified as a criminal, Jesus needed to appear as the leader of a lawless band or armed rebellion.
Having disciples with swords made him look like a rebel to authorities leading the path to the cross.
The swords were for appearance only.
And no harm done for Jesus did not want them use the sword so He was still innocent.
It does matter what those that were against Him thought for there was no harm being done.
But they would want to believe things against Jesus which they were always looking for ways to accuse Him.
Later He tells Peter that he that uses the sword will perish with the sword to use no violence.